Table of Contents Chapter 6 Volcanoes Chapter Preview 6.1 Volcanoes and Plate Tectonics 6.2 Volcanic Eruptions 6.3 Volcanic Landforms 6.4 California Geology

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 1. Igneous rocks form when a. sediment is compacted and cemented. b. rocks are changed by heat and pressure. c. sediment is heated and cooled. d. lava and magma cool and harden.

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 1. Igneous rocks form when a. sediment is compacted and cemented. b. rocks are changed by heat and pressure. c. sediment is heated and cooled. d. lava and magma cool and harden.

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 2. Melted material that erupts from a volcano is called a. magma. b. sediment. c. lava. d. mica.

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 2. Melted material that erupts from a volcano is called a. magma. b. sediment. c. lava. d. mica.

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 3. Why do volcanoes erupt? a. They are hot and fiery. b. They form beneath the ocean floor. c. Gases in magma expand as it rises to the surface. d. Lava is a pure liquid.

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 3. Why do volcanoes erupt? a. They are hot and fiery. b. They form beneath the ocean floor. c. Gases in magma expand as it rises to the surface. d. Lava is a pure liquid.

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 4. Which of these does NOT rapidly change Earth’s land surface? a. earthquakes b. mountain building c. landslides d. volcanic eruptions

Chapter Preview Questions Chapter 6 Volcanoes Chapter Preview Questions 4. Which of these does NOT rapidly change Earth’s land surface? a. earthquakes b. mountain building c. landslides d. volcanic eruptions

Chapter 6 Volcanoes What causes volcanoes, and how do they change Earth’s surface? You know that if you want to open a bottle of soda, you must do so carefully. Otherwise, the soda might spray out of the bottle as soon as you loosen the cap. What causes the soda to rush out with such force? How is this similar to what happens when a volcano erupts? Explain.

Use Clues to Determine Meaning Chapter 6 Volcanoes Use Clues to Determine Meaning Unfamiliar words Hot spot is the subject of the sentence. Some volcanoes result from hot spots in Earthís mantle. A hot spot is an area where material from within the mantle rises and then melts. A volcano forms above a hot spot when the hot material erupts through the crust and reaches the surface. A hot spot in the ocean oor can gradually form a series of volcanic mountains. For example, the Hawaiian Islands formed one by one over millions of years as the Pacific plate drifted over a hot spot. Definition, follows boldface Explanation Example

Chapter 6 Volcanoes Apply It! Review the clues to the meaning of hot spot. Then complete the following. 1. What clue tells you that hot spot might be followed by a definition? The term is in boldface and is the subject of the sentence. 2. What example helps you understand hot spots? The Hawaiian Islands formed one by one over millions of years as the Pacific plate drifted over a hot spot

Chapter 6 Volcanoes End of Chapter Preview

Section 1: Volcanoes and Plate Tectonics Chapter 6 Volcanoes Section 1: Volcanoes and Plate Tectonics Where are most of Earth’s volcanoes found? How do hot spot volcanoes form?

Volcanoes and Plate Boundaries Chapter 6 Volcanoes Volcanoes and Plate Boundaries Volcanic belts form along the boundaries of Earth’s plates.

Volcanoes and Plate Boundaries Chapter 6 Volcanoes Volcanoes and Plate Boundaries Volcanoes often form where two oceanic plates collide or where an oceanic plate collides with a continental plate. In both situations, an oceanic plate sinks through a trench. Rock above the plate melts to form magma, which then erupts to the surface as lava.

Hot Spot Volcanoes Chapter 6 Volcanoes A volcano forms above a hot spot when magma erupts through the crust and reaches the surface.

Click the PHSchool.com button for an activity about volcanoes. Chapter 6 Volcanoes More on Volcanoes Click the PHSchool.com button for an activity about volcanoes.

End of Section: Volcanoes and Plate Tectonics Chapter 6 Volcanoes End of Section: Volcanoes and Plate Tectonics

Section 2: Volcanic Eruptions Chapter 6 Volcanoes Section 2: Volcanic Eruptions What happens when a volcano erupts? What are the two types of volcanic eruptions? What are a volcano’s stages of activity?

Magma Reaches Earth’s Surface Chapter 6 Volcanoes Magma Reaches Earth’s Surface When a volcano erupts, the force of the expanding gases pushes magma from the magma chamber through the pipe until it flows or explodes out of the vent.

Composite Volcano Eruption Activity Chapter 6 Volcanoes Composite Volcano Eruption Activity Click the Active Art button to open a browser window and access Active Art about composite volcano eruption.

Magma Composition Chapter 6 Volcanoes Magma varies in composition and is classified according to the amount of silica it contains. The graphs show the average composition of the two types of magma. Use the graphs to answer the questions.

Magma Composition Chapter 6 Volcanoes Reading Graphs: Study both graphs. What materials make up both types of magma? Silica, other oxides, and other solids.

Magma Composition Chapter 6 Volcanoes Reading Graphs: Which type of magma has more silica? About how much silica does this type of magma contain? Rhyolite-forming magma; about 70 percent.

Magma Composition Chapter 6 Volcanoes Estimating: A third type of magma has a silica content that is halfway between that of the other two types. About how much silica does this type of magma contain? About 60 percent

Magma Composition Chapter 6 Volcanoes Predicting: What type of magma would have a higher viscosity? Explain. Rhyolite-forming magma would have higher viscosity because it is higher in silica.

Kinds of Volcanic Eruptions Chapter 6 Volcanoes Kinds of Volcanic Eruptions Within the last 150 years, major volcanic eruptions have greatly affected the land and people around them.

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Section 3: Volcanic Landforms Chapter 6 Volcanoes Section 3: Volcanic Landforms What landforms do lava and ash create? How does magma that hardens beneath the surface create landforms?

Landforms From Lava and Ash Chapter 6 Volcanoes Landforms From Lava and Ash Volcanic eruptions create landforms made of lava, ash, and other materials. These landforms include composite volcanoes, shield volcanoes, cinder cone volcanoes, and lava plateaus.

Landforms From Lava and Ash Chapter 6 Volcanoes Landforms From Lava and Ash A caldera forms when an volcano’s magma chamber empties and the roof of the chamber collapses. The result is a large, bowl-shaped caldera.

Landforms From Magma Chapter 6 Volcanoes Features formed by magma include volcanic necks, dikes, and sills, as well as batholiths and dome mountains.

Batholiths Chapter 6 Volcanoes A batholith is a mass of rock formed when a large body of magma cools inside the crust. Several large batholiths form the core of mountain ranges in western North America. Half Dome in Yosemite National Park, California, is part of the Sierra Nevada batholith.

Links on Volcanic Effects Chapter 6 Volcanoes Links on Volcanic Effects Click the SciLinks button for links on volcanic effects.

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Section 4: California Geology Chapter 6 Volcanoes Section 4: California Geology How does plate tectonics help to explain features of California’s geology?

Plate Tectonics and California Chapter 6 Volcanoes Plate Tectonics and California The movements of three plates have shaped the geologic features of California over millions of years.

Plate Tectonics and California Chapter 6 Volcanoes Plate Tectonics and California Many geologic processes worked together to form California’s landscape of volcanoes, faults, mountain ranges, and basins.

End of Section: California Geology Chapter 6 Volcanoes End of Section: California Geology

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